1. Technical Field
Example embodiments of the present invention relate to a method of driving a light source, a light source apparatus for performing the method, and a display apparatus that includes the light source apparatus. More particularly, example embodiments of the present invention relate to a method of driving a light source to stabilize the light source, a light source apparatus for performing the method, and a display apparatus that includes the light source apparatus.
2. Related Art
Generally, liquid crystal display (LCD) devices, among various flat panel display devices, have various advantages, such as thinness, lighter weight, lower driving voltage, and lower power consumption compared to other display devices, such as cathode ray tube (CRT) and plasma display panel (PDP) devices. As a result, LCD devices are widely employed for various electronic devices such as monitors, lap top computers, and cellular phones. The typical LCD device includes an LCD panel that displays an image using a light-transmitting ratio of liquid crystal molecules, and a backlight assembly disposed below the LCD panel to provide the LCD panel with light.
The backlight assembly includes a light source for emitting light. The light source may include, for example, any of a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), or a light-emitting diode (LED). In general, the LED has low power consumption and high color reproducibility, so that the LED has been employed as a light source of the LCD device.
Recently, in order to prevent a contrast ratio of an image from being degraded, a method of local dimming a light source has been developed, which individually controls light amounts according to position to drive the light source. In the method of local dimming the light source, the light source is divided into a plurality of light-emitting blocks to control a light amount of the light-emitting blocks in correspondence with dark and white of a display area of the LCD panel corresponding to the light-emitting blocks. For example, driving current amounts provided to LEDs positioned at a dark area of an image may be decreased to decrease light amount, and driving current amounts provided to LEDs positioned at a bright area of an image may be increased to increase light amount.
When the backlight assembly employs a local dimming method using LEDs, the backlight assembly may include multiple strings of LEDs that are connected in parallel and a multi-channel current control circuit for providing the strings with a driving current. The strings may have a structure in which the LEDs are connected in series.
The multi-channel current control circuit generally consumes a voltage deviation between the LED strings as power to uniformly control driving currents flowing through the LED strings. Thus, damage to circuit elements may be generated due to heat produced from the multi-channel current control circuit.